Arnica. COMPOSIT.E. 3gl 



Gray, I.e. A. Clayton!, Fi\Tsh,V].u. 527. Doromcnm acaide,Walt. da. 205. D.nudicauk, 

 Michx. Fl. ii. 121. — Piue barreus, &c., Penu. to Florida. 



* * Radical leaves mostly cordate at base, on slender or .sometimes winged petioles: rootstoclis 

 slender and creeping. Pacific and Rocliy Mountain species. 



-1- Rays wanting or rarely some rudiments: cauline leaves sometimes by disjunction alternate, 

 some of them petioled, irregularly dentate: heads ratljcr numerous, paniculate. 

 A. parviiiora, Gray, a foot high, slender, pubescent, even the pedtiucles but slightly 

 glandular : lea\es narrowly deltoid or oblong, truncate or aljrupt at base, an inch or two 

 long : involucre 4 or 5 lines high, about 20-flowered ; its linear bracts sparsely pubescent : 

 akenes not pubescent, minutely glandular. — Proc. Am. Acad. vii. 36.3, & Bot. Calif, i. 41.''). 

 — California, in Humboldt Co., Bolauder. Also af some .station north of San Franci.-ico 

 Bay, G. R. Vasei/. 



A. disooidea, Bextti. a foot or two high, stouter, more or less villous and viscid : radi- 

 cal aud lowest cauline leaves from ovate with truncate or abruptly cuueate base to cordate, 

 not rarely wing-petioled : involucre half-inch liigh, 30-50-flowered, usually \-ery villous and 

 glandular; its bracts lanceolate or linear : akenes pubescent. — PI. Ilartw. 319; Gray, Bot. 

 Calif. 1. c, Avith a part of ^1. cordijolia. — Wooded hills in tlie coast ranges of California, from 

 San Luis Oliispo Co. northward to Wa,shington Terr. ; first coli. by Hartv;eg. Northwardly 

 seems to pass into A. cordlfolia. 



-1— -4— Rays conspicuous and elongated, rarely wanting; cauline leaves all opposite, in one or 

 two or at most three pairs, broad, usually membranaceous, dentate or denticulate. 



"A. oordifolia, Hook. A foot or two, or when alpine a span or two high, pubescent, or the 

 stems hirsute and peduncles villous : lower cauline as well as radical leaves long-petioled, 

 deeply cordate, yet sometimes only ovate ; upper cauline small, sessile : heads few, in smaller 

 plants solitary : involucre two-thirds inch long, pubescent or villous : rays commonly inch 

 long: akenes more or less hirsute. — Fl. i. 331 ; Torr. & Gray, Fl. ii, 450. A. macrophijUa, 

 Nutt. Trans. Am. Phil. Soc. 1. c. 407. Senecio Cnnnnijii, Klatt in Abh. Nat. Hist. Gesellsch. 

 XV. 9, is either this or the next. — AYoods and high mountains, Brit. Columbia, and mountains 

 near Saskatchewan, to those of Colorado, Utah, Nevada, andeasteru borders of the Sierra 

 Nevada, California. 



Var. eradiata is an ambiguous form; with smaller and rayless heads, and oblong- 

 ovate at most subcordate leaves. — E. Uregon, Montana, &c. Transition to A. Parri/i. 

 A. latifolia, Boxg. Minutely pubescent or commonly glabrous, with smaller heads than 

 the preceding : only radical leaves cordate or subcordate and petioled ; cauline 2 or 3 pairs, 

 equal, ovate or oval, usually sharply dentate, closely sessile Ijy a broad base, or lowest with 

 contracted base : akenes commonly glabrate or glabrous. — ^^eg. Sitch. 147; Torr. & Gray, 

 I.e. A. Menziesii, Hook. FL i. 331, t. 111. — Pine woods, Alaska and Brit. Columbia to 

 Oregon, and Kocky Jlountains to Colorado and Utah ; first coll. by Mi-nzies. 



"V ar. visoidula. Viscidly pubescent : cauline leaves less broad at base : heads ratlier 

 larger: akenes pubescent. — High Sierra Nevada, California, Greene, Pringle. Aud a very 

 similar plant from Sitka. 



# # # No cordate leaves ; radical leaves petioled, tapering or sometimes abrupt at base: root- 

 stocks usually creeping and slender. "Western and Northern species. 



■1— Leafv to the top: cauline leaves very seldom less than 4 pairs, and the upper not conspicuously 



diminished : heads several or tew, or m smaller plants solitary. 



++ Heads all ivith rays half-inch or more long; plants a foot or two high: the species confluent. 



A. amplexicaulis Nutt. Slightly pubescent or almost glabrous : leaves from ovate to 



lanceolate-oblong, acute or acuminate, all the cauline sessile by a half-clasping base, saliently 



and very acutely dentate: akenes hirsute-pubescent. — Trans. Am. Phil. Soc. vii. 408; Torr. 



& Gray" 1. c. Woods and shaded rocks, Oregon to Brit. Columbia, Nuttall, Li/all, Wallace, 



&c. Broad-leaved forms much resembling the preceding, except in more leafy stems and 

 want of cordate radical leaves : narrower-leaved forms nearly pass into the succeeding. 

 rA Chamissonis Less. From tomentulose- or villous-pubescent to nearly glabrous : 

 'leaves oblono- or oblong-lanceolate, denticulate or dentate, acute or obtuse; lowest tapering 

 into a margined petiole, upper broad at base (sometimes ovate-lanceolate) and somewhat 

 clasping; akenes hirsute-pubescent. — Less, in Linn. vi. 238; DC. Prodr. vi. 317; Torr. & 



